function JumpObj(elem, range, startFunc, endFunc) {
        var curMax = range = range || 6;
       startFunc = startFunc || function(){};
        endFunc = endFunc || function(){};
        var drct = 0;
        var step = 1;

        init();

        function init() { elem.style.position = 'relative';active() }
        function active() { elem.onmouseover = function(e) {if(!drct)jump()} }
        function deactive() { elem.onmouseover = null }

        function jump() {
             var t = parseInt(elem.style.top);
            if (!drct) motionStart();
            else {
                var nextTop = t - step * drct;
                if (nextTop >= -curMax && nextTop <= 0) elem.style.top = nextTop + 'px';
                else if(nextTop < -curMax) drct = -1;
               else {
                    var nextMax = curMax / 20;
                    if (nextMax < 1) {motionOver();return;}
                    curMax = nextMax;
                    drct = 1;
                }
            }
            setTimeout(function(){jump()}, 300 / (curMax+3) + drct * 3);
         }
		function motionStart() {
            startFunc.apply(this);
            elem.style.top='0';
            drct = 1;
        }
		  function motionOver() {
            endFunc.apply(this);
            curMax = range;
            drct = 0;
            elem.style.top = '0';
        }

        this.jump = jump;
        this.active = active;
        this.deactive = deactive;
}